Biogeography of sponge chemical ecology: comparisons of tropical and temperate defenses

Abstract

Examples from both marine and terrestrial systems have supported the hypothesis that predation is higher in tropical than in temperate habitats and that, as a consequence, tropical species have evolved more effective defenses to deter predators. Although this hypothesis was first proposed for marine sponges over 25 years ago, our study provides the first experimental test of latitudinal differences in the effectiveness of sponge chemical defenses. We collected 20 common sponge species belonging to 14 genera from tropical Guam and temperate Northeast Spanish coasts (Indo-Pacific and Mediterranean biogeographic areas) and conducted field-based feeding experiments with large and small fish predators in both geographic areas. We use the term global deterrence to describe the deterrent activity of a sponge extract against all of the predators used in our experiments and to test the hypothesis that sponges from Guam are chemically better defended than their Mediterranean counterparts. Sympatric and allopatric deterrence refer to the average deterrent activity of a sponge against sympatric or allopatric predators. All of the sponges investigated in this study showed deterrent properties against some predators. However, 35% of the sponge species were deterrent in at least one but not in all the experiments, supporting the idea that predators can respond to chemical defenses in a species-specific manner. Tropical and temperate sponges have comparable global, sympatric, and allopatric deterrence, suggesting not only that chemical defenses from tropical and temperate sponges are equally strong but also that they are equally effective against sympatric and allopatric predators. Rather than supporting geographic trends in the production of chemical defenses, our data suggest a recurrent selection for chemical defenses in sponges as a general life-history strategy.

Chemical bioactivity of sponges along an environmental gradient in a Mediterranean cave

“…it has been shown that many of the bioactive compounds have an antipredatory function (e.g. Chanas and Pawlik, 1995;Pawlik et al, 1995;Becerro et al, 2003;Burns et al, 2003). occasionally, although rarely, an allelopathic function has been documented (Porter and Targett, 1988;Turon et al, 1996a;Thacker et al, 1998;engel and Pawlik, 2000).…”

Antibiotic, cytotoxic and enzyme inhibitory activity of crude extracts from Brazilian marine invertebrates

“…However, only a limited number of sponge samples have been screened. Also recently, a biological screening related the activities of sponge extracts from samples collected in tropical (Guam) and temperate (Indo-Pacifi c and Mediterranean) biogeographical areas, but of a limited number (20) of sponge species (Becerro et al, 2003). Therefore, it is of interest to screen a large number of sponge extracts, in order to verify the percent of active extracts and the relatedeness with the taxonomy of the sponges which yielded the most active crude extracts.…”

Chemical mediation of interactions among marine organisms

“…Tropical and temperate sponges had comparable deterrence suggesting that chemical defenses from both tropical and temperate sponges were equally effective against predators. 231 In addition to predator defense, sponge extracts have been shown to display antifouling, antimicrobial, and allelopathic activities. For example, zooanemonin 43 and 3,4,5,6-tetrahydromethyl-3,6-dimethyl-4-pyrimidinecarboxylic acid 44 isolated from Protophlitaspongia aga collected in Palau have been reported to inhibit the settlement of cyprid larvae from Balanus amphiriteP 2 Recently, with the development of new marine microbiological techniques, the focus of sponge chemical ecology is moving toward antimicrobial activities of sponge extracts and metabolites.…”